execline is a very light, non-interactive
scripting language, which is similar to a shell.
Simple shell scripts can be easily rewritten in
the execline language, improving performance
and memory usage. execline was designed for
use in embedded systems, but works on most
Unix flavors.

Firejail is a SUID sandbox program that reduces the risk of security breaches by restricting the running environment of untrusted applications using Linux namespaces. It currently implements hostname, filesystem, PID, IPC, and networking stack isolation, and it runs on any recent Linux system. It includes a sandbox profile for Mozilla Firefox. Firejail also expands the restricted shell facility found in bash by adding Linux namespace support. It supports sandboxing specific users upon login. The software also includes a small monitoring utility, firemon.

V6 Thompson Shell Port provides two ports of the original /bin/sh from Sixth Edition (V6) UNIX (circa 1975). osh is an enhanced port of the shell, and sh6 is an unenhanced port of the shell. This project also includes glob6, if, goto, and fd2 as external shell utilities. While they remain external for compatible use by sh6, these utilities are integrated into osh to improve shell performance.

Rodent filemanager is a fast, small, and powerful file manager. Its emphasis is on ease of use for the advanced user, not the computer illiterate. Rodent filemanager (a.k.a. xffm >= 4.6.0) is the next step in the evolution of Xffm, now with a threaded design optimized for multicore processors.

The klish is a framework for implementing Cisco-like command-line interfaces on Unix systems. It is configurable through XML files. "Klish" stands for "Kommand Line Interface SHell". The klish is a fork of clish-0.7.3. The original clish was developed by Graeme McKerrell. The klish adds some new features, but is compatible (as much as possible) with clish's XML configuration files.

The MirBSD Korn Shell (mksh) is an actively developed successor of pdksh (the Public Domain Korn Shell), aimed at producing a shell good for interactive use, but with the primary focus on scripting. It is intended to be portable to most *nix-like operating systems as long as they're not too obscure. mksh incorporates improvements from OpenBSD and Debian, as well as bugfixes and enhancements developed for the MirOS, FreeWRT, and MidnightBSD projects and Android. The emacs command line editing mode is UTF-8 capable, and Byte Order Marks are ignored in scripts. The shell supports large files, as well as all pdksh and some csh, AT&T ksh, zsh, and GNU bash features, is compatible with the Bourne shell and POSIX (within limits), has no limit on array sizes, and incorporates some other useful builtins and features. While being already fast and small (without losing functionality), flags to make it even smaller can be given at compile time. An interactive shell reads "~/.mkshrc" on startup.

Jailkit is a set of utilities to allow quick creation of
limited user accounts in a chroot jail. It contains a safe logging daemon, shells that can restrict users, utilities to start daemons in a chroot jail, and utilities for easy setup of chroot jails.

Tcsh is an enhanced but completely compatible version of the Berkeley UNIX C shell. It is a command language interpreter usable both as an interactive login shell and a shell script command processor. It includes a command line editor, programmable word completion, command and file name completion, listing, spelling correction, a history mechanism, job control, and a bunch of small additions to the csh shell itself.